Cylinder gauge



March 1 1927- c. c. RoBBlNs CYLINDER GAUGE I7 Lz e7 L/Or:

Chest-e7" 6. Robbgns. Z5( his afy.

Patented Mar. 1 1927.

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@BESTER C. RBBINS, OF WALTHAM, MASSACHUSETTS, ASSIGNOR T B. C. AMES C0., 0F WALTHAM, MASSACHUSETTS, CORPORATION 0F MASSACHUSETTS.

CYLINIDERr GAUGE.

Application med December ie, i922. serial No. comes.

The invention relates to measuring gauges and has among its objects the' elimination of back lash and lost motion in the indicating mechanism. The invention will be best iinderstood from the following description when read in the light of the accompanying drawing of a specific embodiment of the 1nvention, while the scope of -the invention will be more particularly pointed out in the appended claims. Referring to the drawings:

Figure 1 represents a front elevation of a cylinder gauge embodying the invention. Fig. 2 represents a rear elevation of the cylinder gauge, the back plate thereof being removed.

Fig. 3 is a central vertical section taken u i on the line 3-3 of Fig. 2.

Fig. 4: is a detail section taken on. theline 1-4ofFig.2.

Fig. 5 is an enlarged detail view illustrating the manner in which the main gear and take-up gear mesh with the center pinion to prevent back-lash therebetween.

Like numerals refer to like parts throughout the several views of thedrawings.

In the drawings, 10 represents a casing of a cylinder gauge, l1 isa dial, which herein ismovable relative to the casing, provided with gradnations 12` preferably indicating thousandths of an inch, 13 is a bezel secured in any suitable manner to the casing 10, and

414 is. a crystal mounted .in the usual well known manner in the bezel 13. Secured in any suitable manner in the casing 10 adjacent to the rear of the dial 11 is a front plate 15 at the center' of which a center staH 16 is located. rl`he center staff 16, which herein -rotates the indicat' g hand, ismounted to rotate in `the front plate 15 and also in a bearing member 17 fast to the rear of said center plate, and fast to said staff at the forward end thereof and located adjacent .to the front face of the dial 11 is an indicatin hand 18. Y,

ln he present construction rigidly secured in any desired'manner in the casing 10 is a sleeve 19 at the lower end of whigh a stationary work enga 'ng member 20, preferably constructed of iirdened steel, is rigidly secured in any desired manner. Oppositely disposed tothe stationary work enga ing member 20, and located ,in longitu inal alignmenttherewith is a yielding work engaging member 21. The yielding work en- 'tion the motion of the gaging member 21 as illustrated embodies therein a rod 22 slidably mounted in the sleeve 19 and also in a sleeve 23 fastened in the opposite side of the casing 10 from the sleeve 19. A member 24 preferably constructed of hardened steel is illustrated as detachably secured to the outer extremity of the rod 22 and herein constitutes a part of the. yielding work engaging member. As illustrated the rod 22 is prevented from rotating in the sleeves 19 and 23 by a pin -25 fast to said rod and 26 in a guide member 27 fast to the front plate 15. A spring 28 is located within the sleeve 19, one end of said spring contacting with the inner extremity of the stationary work engaging member 20 and the other end thereof Contactin with the inner extremity of the rod 22 an said spring always acts to force the yielding work engaging member 2 1 outwardly until `thepin 25 contacts with a stop pin 29 located within the guide member 27 and-extending across the groove 25 at which time said `yielding work engaging member is located in its normal position.

ln the present" embodiment of the invenyielding work engaging member 21`is transmitted to the staff 16 carrying the indicating hand 18by mechanism as follows z-Provided upon the 'rod 22 and preferably formed integra-l therewith are rack teeth 30 which mesh with and drive a pinion( 31 fast to a staiil 32, the latter being rotatably' mounted at one \end thereof in a bearing bracket 33 and at its other end in the front plate 15, the bearing bracket and front plate constituting spaced bearings for said staff. Adgear 34 preferably having a collet ,35 rigi ly fastened thereto and constitutin a hub therefor is rigidly fastened to t e staff v32 in any desired manner, and said gear 34 meshes with and drives a center pinion 36 rigidly fastened to the center stall' 16. Another gear- 37 constituting a take-up gear preferably having a collet -38 rigidly fastened thereto and constituting a hub therefor, is loosely mounted upon the hubof the gear 34 and also meshes with thev center pinion 36. A spiral spring projecting into a groovensl and against the opposite sides of the teeth `being force trated clearly in Fig. 5 and the result is the Vtion of the arrow a, thereby rotatin of the center pinion 36 from that to which the poweris applied by the gear 34 when the yielding work engaging member 21 is inwardly. his action is illuselimination of any back-lash between the gear 34 and the center pinion 36. A back plate 40 is fastened to the casing 10 and entirel7 closes said casing at the rear thereof, an said back plate 40 may, if it is so desired, be utilized for fastening the casin 10 to a suitable base which is often employe J inconnection with devices of this character to facilitate the positioning of the device upon the work. In the present instance, however, it forms no part of the invention. In the operation of the device illustrated, which is employed in a manner well known to those skilled in the art where very accurate measurements are desired, as the ieldin work engaging member 21 is forced by bein brought into contact with the wor the rac 30 meshing with the pinion 31, will cause the staff 32 and gear 34 fast on said sta to be rotated in the direi):-

t e center pinion 36 in the direction o the arrow b as illustrated in Fig. 5. The takeup gear 37 being loosely mounted upon the gear 34 and also meshing with the center inion 36 will also be rotated by the latter in the direction of the arrow a but at the same time the action of the sprin tend to force the take-up Gear 37 in the direction of the arrow c andnif there happens to be any clearance between the teeth of the gear 34 and the teeth of the center pinion 36, which is generally the case, the backlash caused by the presence of this clearance will be eliminated.

It will be understood that within the sco e of my invention' wide deviations maybe of described herein without departing from the s irit of the invention.

I caim:

1. A gau e comprising, in combination, a

casing, a ial, an indicating hand or the like, means including a center pinion for producing relative movement between said ial and hand, a yielding work engaging member mounted for reeiprocation substantially diametrically of said casing, means `operatively to connect said work engaging v member and said center pinion and embodying therein a gear meshing with said center pinion, a take-up gear mounted concentric with said iirst-named gear and meshing with said center pinion, a spring operatively connected to said take-up gear and acting throu h said center pinion to ur e rotation of said first-named gear and ta e up lost motion in said second mentioned means, a stai acting as a common support for said 39 willn (said center pinion.

2. A gauge comprising, inA combination, a casing, a dial an indicating hand or the like means including a center pinion for pro ucing relative movement between said dial and hand, a yielding work engaging member embodying therein a. rod mounted for reciprocation substantially diametricall of said casingl and provided with a rack tl'lereon, means operatively to connect said rack and said center pinion and embodying therein a ear meshing with said center p inion, a ta e-up gear, means for mounting said take-up gear for free rotationfrelative to said first-named gear, said take-up gear also meshing with said center pinion, and a torsion spring connecting said take-up gear to a fixed part of said gauge.

3. A gau e comprising, in combination, a dial, an in icating hand or the like, means including a center pinion for producin relative movement a yielding work engaging member, a rack fast to said member, a sta pivotal? carried by said casing at one side of sai rack, a pinion yfast to said staff and meshing with said rack, a gear also fast to said staff and meshing with said center pinion, a take-up gear and a torsion spring situated between said gear and said pinion fast on said stati' and concentrically of said stati, said takeup gear being rotatable relatively tothe other gear and meshing with said center pinion, and said torsion spring being fixed to said take-up gear for urging said takeup gear to rotate said center pinion. made from the particular embodiment there- 4. A gauge having in combination, indicating means, movable work engaging means, mechanism actuated by said work engaging means for operating said indicating means, said mechanism comprising a meshing gear and pinion, said gear havin a hub, a secondlgear mounted on said hu concentrically with and being rotatable relatively to said irst named gear, said secfi ondgear also meshing with said pinion,

between said dialv and and,f

ioo

iis

f torsion spring first named gear to rotate.

6. A gauge comprising, in combination,y

said first named gear and also meshing with said first named pinion, said second gear being positioned between said bearings and belng rotatable relatively to.v said staff, a

located between said bearings, said sprlng being concentric with said gears and connecting said second gear to a fixed part of the casin forurging said vsecond gear to rotate 4sald pinion in one direction -whereby said pinion urges said an indicating hand, a dial, means including a pinion for producing relative movement between said hand and dia1,' a yieldin work engaging means; means for operative y connecting said pinion and work engagin means comprismg a pivotally mounted sta having fast thereon in spaced relation a Adriv ing gear and a drlven pinion, the former for ,drlvm said first mentionedpinion .and the latter or driving said staff; a take-up gear of the same pitch and numberxofteeth as said drivinggear rotatably mounted on said staff between said driving gear and driven pinion, said driving gear and driven pin- 1on affording shou ders on vsaid staff for holding Said take-up gear on said staff whereby said staf with said driving gear,

drivenpinion and'take-up gear can be assembled and handled as a unit; said takeup gear also meshing with said first men-fv tioned pinion, and a torsion spring surrounding said staff and connectingsaid take-up gear to a lixed part of said gauge.

In testimony whereof I have hereunto set my hand.

CHESTER C. ROBBINS. 

